WP7备注(32)(Relative Source|在自定义控件的属性中为子控件的属性赋值|INotifyPropertyChanged)

Relative Source:

<TextBlock Text="{Binding RelativeSource={RelativeSource Self},
Path=FontFamily}" />

在自定义控件的属性中为子控件的属性赋值:

public partial class BorderedText : UserControl
{
public static readonly DependencyProperty TextProperty =
DependencyProperty.Register("Text",
typeof(string),
typeof(BorderedText),
new PropertyMetadata(null));

public string Text
{
set { SetValue(TextProperty, value); }
get { return (string)GetValue(TextProperty); }
}
}

<TextBlock Text="{Binding ElementName=this, Path=Text}"/>

用于自定义控件的子控件的属性开放,如上面那句代码,当BorderedText的Text属性赋予新值的时候,内部子控件TextBlock会自动绑定所赋的新值

INotifyPropertyChanged:

实现此接口的数据源类,也可以进行实时更新

public int Second
{
protected set
{
if (value != sec)
{
sec = value;
OnPropertyChanged(new PropertyChangedEventArgs("Second"));
}
}
get
{
return sec;
}
}

protected virtual void OnPropertyChanged(PropertyChangedEventArgs args)
{
if (PropertyChanged != null)
PropertyChanged(this, args);
}

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<StackPanel DataContext="{Binding Source={StaticResource clock}}"
Orientation="Horizontal"
HorizontalAlignment="Center"
VerticalAlignment="Center">
<TextBlock Text="{Binding Path=Hour}" />
<TextBlock Text="{Binding Path=Minute,
Converter={StaticResource stringFormat},
ConverterParameter=':{0:D2}'}" />
<TextBlock Text="{Binding Path=Second,
Converter={StaticResource stringFormat},
ConverterParameter=':{0:D2}'}" />
</StackPanel>
</Grid>